Method for manufacturing aluminum alloy plastically-processed article

Abstract

An object of the present disclosure is to provide a method for manufacturing an aluminum alloy plastically-processed article, capable of preventing a burning crack from occurring due to processing heat generated during plasticity processing while maintaining a solution-treatment temperature of an aluminum alloy material for ensuring a mechanical strength thereof. A method for manufacturing an aluminum alloy plastically-processed article, includes a step of performing a solution treatment for an aluminum alloy material by heating and maintaining the aluminum alloy material at a solution-treatment temperature, a step of performing plasticity processing for the aluminum alloy material subjected to the solution treatment, and steps of cooling the plastically-processed aluminum alloy material at a time at which the step of the plasticity processing is completed, and aging the cooled aluminum alloy material. The method further includes pre-plasticity-processing cooling step of cooling the aluminum alloy material subjected to the solution treatment.

What is claimed is: 
     
       1. A method for manufacturing an aluminum alloy forged article, comprising:
 performing a solution treatment for an aluminum alloy material by heating and maintaining the aluminum alloy material at a solution-treatment temperature T 1 ; 
 performing forging at a temperature higher than 520° C. for the aluminum alloy material subjected to the solution treatment; and 
 cooling the forged aluminum alloy material upon completing the forging, and aging the cooled aluminum alloy material, wherein 
 the method further comprises, before starting the forging, a pre-forging cooling step of cooling the aluminum alloy material subjected to the solution treatment at a temperature of no less than 520° C. while maintaining the aluminum alloy material subjected to the solution treatment in a solution state. 
 
     
     
       2. The method for manufacturing an aluminum alloy forged article according to  claim 1 , wherein in the ore-forging cooling step, after the aluminum alloy material subjected to the solution treatment is cooled, a temperature T 2  of the cooled aluminum alloy material is adjusted so that, in the forging step, a temperature T 21  of the aluminum alloy material which has been subjected to the forging and hence in which processing heat has been generated remains lower than a lower limit value Tmi of a burning-crack occurring temperature range,
 wherein the burning-crack occurring temperature range is a temperature range at which cracking occurs. 
 
     
     
       3. The method for manufacturing an aluminum alloy forged article according to  claim 1 , wherein in the pre-forging cooling step, after the aluminum alloy material subjected to the solution treatment is cooled, a temperature T 2  of the cooled aluminum alloy material satisfies the following relationship:
   ( Tmi− 45° C.)≤ T 2≤( Tmi− 10° C.).
 
 
     
     
       4. The method for manufacturing an aluminum alloy forged article according to  claim 1 , wherein the solution-treatment temperature T 1  satisfies the following relationship:
   ( Tmi− 65° C.)≤ T 1≤( Tmi− 5° C.).
 
 
     
     
       5. The method for manufacturing an aluminum alloy forged article according to  claim 1 , wherein the pre-forging cooling step is performed for a cooling time of no lower than 0 seconds and no higher than 97 seconds.